Miniaturized microwave antenna

Abstract

A miniaturized antenna is described with at least a ceramic substrate (10) and a metallization, particularly designed for use in the high-frequency and microwave ranges. The antenna is characterized in that the metallization is a surface metallization which is formed by a feed terminal (12) for electromagnetic energy to be radiated, by at least a first metallization structure (30), and by a conductor track (20) extending along at least part of the circumference of the substrate (10), which track connects the feed terminal to the at least one first metallization structure (30), which first metallization structure (30) comprises a first conductor track portion (31) extending from a side of the substrate lying opposite the feed terminal (12) towards the feed terminal and a first metallization pad (32). The antenna can be provided on a printed circuit board by surface mounting and has a great impedance and radiation bandwidth, so that it is particularly suitable for use in mobile telephones operating in the GSM and UMTS bands.

Description

1. Field of the InventionThe invention relates to a miniaturized antenna with at least a ceramic substrate and a metallization, in particular for use in the high-frequency and microwave range. The invention further relates to a printed circuit board and a mobile telecommunication device with such an antenna.2. Description of the Related ArtFollowing the trend towards ever smaller electronic components, in particular in the field of telecommunication technology, all manufacturers of passive and / or active electronic components are intensifying their activities in this field. Particular problems then arise especially with the use of electronic components in the high-frequency and microwave technology fields, because many properties of the components are dependent on their physical dimensions. This is based on the generally known fact that the wavelength of the signal becomes smaller with increasing frequency, which again has the result that the supplying signal source is influenced in ...

AI Technical Summary

Benefits of technology

Furthermore, an antenna is to be provided which renders it possible to dispense at least substantially with passive adaptation circuits and which is also suitable for surface mounting by the SMD (surface mounting device) technology on a printed circuit board.

This solution combines many advantages. Since the feed terminal is part of the metallization present on the surface of the substrate, no contact pins or similar items are required for feeding-in of the electromagnetic energy to be radiated. This means that the antenna can be provided by surface mounting (SMD technology) on a printed circuit board (together with the other components). The size of the antenna can also be further reduced thereby, and the antenna is mechanically substantially more stable and insensitive to external influences.

Problems solved by technology

Particular problems then arise especially with the use of electronic components in the high-frequency and microwave technology fields, because many properties of the components are dependent on their physical dimensions.

Since these dipole antennas are too large for many applications, however, in particular for mobile telecommunication (the wavelength for the GSM900 range is, for example, approximately 32 cm), alternative antenna structures are utilized.

Although antennas of this type are widely used, they do have considerable disadvantages.

Furthermore, the .lambda. / 4 monopoles cannot be directly soldered onto the printed circuit board because the wire antennas are mostly used as pull-out members, for example in mobile telephones.

This means that expensive contacts are necessary for the information exchanged between the printed circuit board and the antenna.

A further disadvantage of antennas of this type is the mechanical instability of the antenna itself as well as the adaptation of the housing to the antenna made necessary by this instability.

If a mobile telephone, for example, is dropped, the antenna will usually break off, or the housing is damaged in that location where the antenna can be pulled out.

These antennas, however, have the disadvantage that at least portions of the conductor tracks extend inside the substrate, and that accordingly the substrate is to be manufactured in several layers and with a certain minimum size, which may be comparatively expensive.

In addition, it is not possible with this arrangement of the conductor tracks to carry out an electrical adaptation of the conductor tracks to a concrete constructional situation in the finished state, because the conductor track is no longer accessible, or only partly accessible.

It was also found that passive circuits for impedance adaptation are unnecessary, because such an adaptation can be achieved through a change in the fully accessible metallization (for example achieved by laser trimming) with the antenna in the incorporated state.

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